Premium
A kinetic isotope effect during ice formation by water freezing
Author(s) -
Souchez R.,
Jouzel J.,
Lorrain R.,
Sleewaegen S.,
Stiévenard M.,
Verbeke V.
Publication year - 2000
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2000gl006103
Subject(s) - deuterium , kinetic isotope effect , kinetic energy , equilibrium fractionation , isotope , isotope fractionation , clear ice , mass independent fractionation , chemistry , diffusion , sea ice , atmospheric sciences , geology , fractionation , arctic ice pack , thermodynamics , antarctic sea ice , climatology , physics , chromatography , quantum mechanics
A kinetic isotope effect is known to occur during ice formation from water vapour in a cloud ; it is due to the difference in molecular diffusivities in air of HDO and H 2 18 O molecules. A similar effect is likely during water freezing since diffusion coefficients of HDO and H 2 18 O are also different in liquid water. Their values are however less different from each other than those in air. Therefore, such a kinetic isotope effect during water freezing is less frequently observed in Nature. This paper describes a situation in Antarctica where this effect is conspicuous in icings (aufeis). In this type of ice indeed there is no relationship between δD (or δ 18 O) and deuterium excess whereas a clear inverse relationship between these parameters exists in ice formed by water freezing when equilibrium isotopic fractionation applies. This kinetic effect is potentially present in hail within clouds, in infiltration ice (formed during sea ice growth) and in some kinds of ground ice.